The present invention relates to a targeted or destination call control for lifts or elevators according to the definitions of the patent claims.
In known manner an elevator control serves the purpose of serving car calls to the various floors of the building. The drive of the elevator knows as commands merely the instructions xe2x80x9ctravel upwardlyxe2x80x9d, xe2x80x9ctravel downwardlyxe2x80x9d, xe2x80x9cdoor openxe2x80x9d and xe2x80x9cdoor closexe2x80x9d.
In larger buildings usually a group of two to eight elevators is installed, from which it is now necessary to select that elevator which appears the most suitable for a newly input car call from a floor, a so-termed floor or hall call. As a rule this is the elevator which has the shortest travel path to this floor. If, however, each elevator of the group has to serve, on this travel path, other hall calls beforehand, then passengers will board at the floors, the destination of whom is known only when they have pressed the corresponding car buttons. The allocation of a hall call to an elevator thus becomes problematic, since permanent uncertainty about the destinations to be traveled to exists.
Accordingly, in the elevator industry numerous experiments can be observed to skillfully xe2x80x9cguessxe2x80x9d the possible destination floors of the passengers by means of use of learning methods on the basis of neuronal networks or genetic algorithms. The effect of such a method is, however, very limited, because merely coarse traffic patterns, such as, for example, the morning upward peak, are identifiable with any certainty. However, it remains unclear what a passenger wants when, for example, he or she calls a elevator on a Monday morning about 10:37 o""clock at the 10th floor of a high-rise office.
Another starting point for the solution of the control problem consists of so-called destination call controls. With a destination call control the passengers, before boarding an elevator or an elevator car, input their desired destination floor, for example by way of a keyboard similar to a telephone, i.e. a so-termed terminal. The boarding floor is known to the destination call control from the position of the terminal. After input of the destination floor, an allocation algorithm of the control ascertains that elevator of the elevator group which enables the quickest and most comfortable transport for the passenger to his or her destination. The terminal indicates to the passenger this elevator of the group of elevators and the passenger can step into the correspondingly marked elevator at his or her own pace. If the elevator stops for boarding, then the destination of the passenger is confirmed, for example, by way of a display device in the door frame. In the car itself, there are no longer present any buttons for the input of destinations. In this manner, through use of a destination call control, passengers with an identical transport destination can be grouped and thereby the transport performance of the elevator system increased.
An example, which is known from the European patent document EP 0 699 617 A1, of such a destination call control is, in addition, in the position of identifying individual passengers. For each identified passenger additional data with respect to boarding position and disembarking position, the passenger space requirement and possible additional service requirements are taken into consideration, by access to a data memory, in the determination of the optimal transport possibility.
This and other conventional destination call controls are based on an intuitive approximation algorithm on the basis of allocation rules. This allocation algorithm is designed and programmed in each instance specifically to requirement. In the case of a travel request, i.e. the destination call, the data related to persons and the installation and detected by way of an appropriate sensor system are passed on to the allocation algorithm and run through the algorithm for determination of the travel sequence.
If new additional travel requests arise during execution of a travel sequence, then the already computed travel sequence is modified to that effect. In that case, however, only simple modifications can be undertaken, which can have the consequence that only a modified travel sequence which is related to a destination call and which is no longer the optimal travel sequence with respect to the changed preconditions is executed. Long waiting times and/or transport times for the passengers can result therefrom. Moreover, interrelationships of individual control options, so-termed service requirements, are not always expressed logically and in unbroken manner in such a fixedly programmed allocation algorithm. Moreover the control software created in requirement-specific form for computation of the travel sequence is regarded as detailed and complicated. It is disadvantageous, in particular, that a once-created allocation algorithm can be subsequently adapted to different customer-specific control requirements only with substantial cost. In practice, for adaptation to changed service requirements a new elevator specific allocation algorithm has to be prepared in each case and implemented in entirety.
The targeted call control for elevator installations according to the present invention concerns an apparatus, which apart from an increase in transport performance is also constructed to be flexible and robust and takes into consideration, in particular, individual and/or collective transport needs of passengers.
For the fulfillment of this object the invention is given by a method for travel sequence planning which is characterized in particular by the fact that a situation-based search process for determining the optimal travel sequence is provided. A solution in terms of device is given by a targeted call control that proposes an organization of the traffic volume with use of a so-termed planning system.
According to the invention there is thus provided in place of a previously employed, use specific fixedly programmed control algorithm, a planning system which is known per se. The planning system operates according to a situation-based search process and determines, related to destination call and proceeding from the instantaneous operational state of the elevator installation and the objective state to be produced of the elevator installation, the situation-specific optimal travel sequence.
The use in accordance with the invention of a situation-based search process essentially offers the advantage that in the case of any relevant change in the instantaneous situation, for example on registration of a new travel request, disruptions in the execution of a travel sequence, or the like, a completely new actual travel sequence is determinedxe2x80x94in the extreme case after each executed travel sequence stepxe2x80x94and the elevator drive then executes this new sequence.
With each registration of a relevant change, for example, in the case of each destination call, the instantaneous operational state and the desired objective operational state of the elevator installation are declaratively combined on the basis of facts in a state description. This state change, which is illustrated in the state description and which is to be achieved, of the elevator installation is passed on to the planning system in translated form as a part of a situation representation, which is described further below. The situation-based search process thus has, with each registered destination call, complete information with respect to the traffic state of the elevator installation. It can accordingly compute the optimal serving of the destination call for a fixed, predefined optimization criterion. This computation process is so designed that in fact the optimum can be found on the basis of the given criterion under real-time requirements.
The determined travel sequence plan is constructed by the planning system in such a manner that the desired state change can be achieved in execution of the travel sequence plan.
An elevator installation with travel sequence planning in accordance with the present invention consequently executes in each instance exclusively the travel sequence representing the optimum for the actual planning situation. The optimization can in that case be carried out on the basis of entirely different criteria, wherein the objectives of optimization result from an increase in the performance of the elevator, a reduction in waiting times and/or serving times and travel times of the passengers or, however, an improvement in a balanced travel management and the like.
The planning process is in advantageous manner limited in time, in that computing performance and memory needs are limited. The search process finds the optimal or approximately optimal travel sequence within these restricted computing resources. So termed xe2x80x9canytimexe2x80x9d algorithms for that purpose are known to the expert and can be used for such a search process.
According to an advantageous embodiment of the search process according to the present invention, the state description is passed on in translated form to the planning system preferably together with an operator description in the situation representation.
The operator description is communicated to the destination call control according to the invention at the time of configuration, preferably on installation of the system with the customer. It contains operators which specify elemental state transitions of the elevator installation. The operators form, as elemental modules for the travel sequence solution to be constructed, the basis of the travel sequence plan to be determined. In the case of each destination call allocation or in the case of solution of a concrete planning task, the planning system selects the operators, which are to be used in the solution, from the operator description and determines concrete values for operator parameters as well as an arrangement sequence in which operators occur in the travel sequence plan. This arrangement sequence specifies the execution sequence of the operators in the plan, thus the travel sequence.
By contrast to previous fixedly programmed allocation algorithms the planning system can be provided with any number of operators, including such which can serve service requirements not yet present on the side of the customer at the moment of installation. If these requirements arise at a later time, then it is merely necessary to communicate to the planning system a corresponding situation representation in which these service requirements are formulated. The system can then immediately solve such tasks. If service requirements arise for which no operators are provided, then the modularity of the operators in a planning system ensures that new operators can be added in or taken out in simple manner without the already present operators having to be influenced. Elevator installations can thus be adapted very simply and flexibly to changing customer needs with respect to traffic organization by changing the number of operators available for control and also by the definition of the operators themselves.
In the case of control of a group of elevators by the destination call control according to the invention, consideration of the service requirements in continuous operation of the elevator installation takes place without a separate reservation of a elevator of the elevator group having to be carried out for the passenger requiring the respective service. The elevator control and the operators are matched to one another in such a manner that, in principle, any elevator can at any time execute all special service requirements predetermined by way of the situation representation. If needed, the service requirement is quasi call-specifically integrated in the group operation.
The embedding of a planning system as a core of the destination call control is possible in a centralized concept, a decentralized concept or a combination of the central and decentralized concept.
In the case of a construction of the destination call control with a so-termed central job manager this is a decision interface between the terminals and the individual job managers of the elevators. The terminals direct their transport inquiries to the central job manager. The job manager asks each of the job managers of the individual elevators for a transport offer for the respectively registered destination call, i.e. the so-termed job. It is incumbent on the central job manager alone to manage all actual transport inquiries of passengers, i.e. the destination calls, and the booking of the transport requests, i.e., so-termed jobs, to the respectively selected elevator. The terminals receive from the central job manager as a response the identification of the selected elevator, which they thereupon display (for example xe2x80x9cAxe2x80x9d or xe2x80x9cBxe2x80x9d).
The communication between the terminals and the elevators is simple to organize, because all communication runs by way of a central control, i.e. the central job manager. The organization of the jobs takes place at a central job manager in a waiting queue, a so-termed xe2x80x9cfirst in, first outxe2x80x9d data structure. This organization is simple and secures a clear running sequence.
In the case of the central concept the terminals only have to process the destination call input of the passenger as well as the indication of the elevator booked by the central job manager and require for this purpose only simple software. The use of simple and economic terminals makes this possible.
In the case of a decentralized construction of the job manager, the terminals are connected by way of a capable communications network with the job managers of the individual elevators of an elevator group. The terminals directly ask the job managers of the individual elevators for a transport offer for the respectively registered destination call. The terminals independently collect these offers, compare them and determine the optimal booking of the passenger. In the case of a decentralized job manager the organization of the jobs takes place in parallel for several jobs, wherein a desired superimposition of inquiries and bookings is possible.
Further advantages of the decentralized concept of the destination call control reside in thexe2x80x94by comparison with the centralized conceptxe2x80x94faster reaction of the job manager to inquiries, an increased stability of the overall system due to the decentralization and a simplified architecture of the job manager, since a separate central control does not have to be provided.
Insofar as the decentralized embodiment is provided, the terminals are equipped with intelligent booking software. The communication between the terminals and the job managers of the individual elevators is preferably carried out by way of use of contract network protocols. The job managers of the individual elevators are themselves in a position to organize jobs in parallel and to correctly manage their status.
The centralized and decentralized concepts of the job manager can also be combined-with one another in a destination call control. Any number of job managers, which control one or more elevators, can be present in a network.
According to a particularly preferred development of the invention the situation-based destination call control is represented as a multi-agent system, which realizes the entire controls of installation, wherein the planning system is an agent in this multi-agent system. The elevator installation can comprise any number of elevators with any layout. Thus, several elevators can also cooperate with a different number of decks in one group, i.e. a so-termed heterogeneous multi-decker group.
The construction as a multi-agent system enables a modular implementation of the destination call control, in which individual components, i.e. the so-termed agents, for example planning system, doors, drive and taxi driver, can be exchanged as desired without the entire system having to be changed.
An event-controlled activation of the agents in a multi-agent system makes the system substantially more robust relative to occurring errors. If, for example, a shaft door at a story breaks down due to a faulty contact, then either the job manager can cause an evacuation travel or, however, the taxi driver can initially allow the still-present plan to be executed. For further passenger inquiries, the fault can be communicated to the configuration manager which informs all relevant components of the system that temporarily this floor cannot be served by this elevator. A failure of components does not signify immediate failure of the entire system as long as the safety of the passengers is guaranteed.
Further advantageous refinements of the invention are contained in the independent claims.